Effect of stable and unstable loads on post-activation performance enhancement in the countermovement jump
DOI:
https://doi.org/10.63750/f390w842Keywords:
water bag, force-time, jump kinematics, instability trainingAbstract
This study aimed to investigate the practicality of unstable loads and their effect on post-activation performance enhancement (PAPE), observed through force time kinematic variables in the countermovement jump (CMJ). Thirty-four collegiate male athletes participated in a randomized crossover experiment. Athletes were randomly assigned to first complete either the 20.4 kg barbell stable (ST) or 20.4 kg water bag unstable (US) load protocol After a 20-minute rest period, the subjects completed the other protocol. Protocols consisted of a baseline jump, two sets of three consecutive jumps with the load, then a second jump to retest. Force plate data were sampled at 1,000 Hz and predetermined landmarks of the force time curve were utilized to calculate key performance indicators. A two-way repeated measures ANOVA with condition (ST, US) and time (pre, post) as independent variables was used to assess outcome variables. Statistical significance was set at p < .05. No significant interaction or condition effects were present in findings (p > .05). Peak and average braking force (p = .001; p < .001 respectively), braking impulse (p < .001), takeoff velocity (p = .005), jump height (p = .006), center of mass (COM) depth (p = .006), and rate of force development (RFD) (p = .009) were all significantly different between the first and second jump for both ST and US conditions. The results of this study suggest that either stable or unstable loads may produce a PAPE effect, thus increasing the number of modalities available to achieve this outcome.
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Bampouras, T. M., & Esformes, J. I. (2020). Bodyweight squats can induce post-activation performance enhancement on jumping performance: A brief report. International Journal of Physical Education, Fitness and Sports, 9(4), 31–36. https://doi.org/10.34256/ijpefs2044
Bauer, P., Sansone, P., Mitter, B., Makivic, B., Seitz, L. B., & Tschan, H. (2019). Acute effects of back squats on countermovement jump performance across multiple sets of a contrast training protocol in resistance-trained males. Journal of Strength and Conditioning Research, 33(4), 995–1000. https://doi.org/10.1519/JSC.0000000000002422
Beato, M., Stiff, A., & Coratella, G. (2021). Effects of postactivation potentiation after an eccentric overload bout on countermovement jump and lower-limb muscle strength. Journal of Strength and Conditioning Research, 35(7), 1825–1832. https://doi.org/10.1519/JSC.0000000000003005
Blazevich, A. J., & Babault, N. (2019). Post-activation potentiation versus post-activation performance enhancement in humans: Historical perspective, underlying mechanisms, and current issues. Frontiers in Physiology, 10, Article 1359. https://doi.org/10.3389/fphys.2019.01359
Cardona Gómez, J. S., & Rojas Jaramillo, A. (2025). Does post-activation performance enhancement (PAPE) occur with strength exercises on unstable surfaces? Effects on jump and sprint performance in a randomized crossover trial. Retos, 67, 182–195. https://doi.org/10.47197/retos.v67.110599
Chavda, S., Bromley, T., Jarvis, P., Williams, S., Bishop, C., Turner, A., Lake, J., & Mundy, P. (2018). Force-time characteristics of the countermovement jump: Analyzing the curve in Excel. Strength and Conditioning Journal, 40(2), 67–77. https://doi.org/10.1519/SSC.0000000000000353
Corradi, E. F. F., Lanza, M. B., Lacerda, L. T., Andrushko, J. W., Martins-Costa, H. C., Diniz, R. C. R., Lima, F. V., & Chagas, M. H. (2021). Acute physiological responses with varying load or time under tension during a squat exercise: A randomized cross-over design. Journal of Science and Medicine in Sport, 24(2), 171–176. https://doi.org/10.1016/j.jsams.2020.07.015
Crosbie, L., Langdon, D., & Thompson, N. (2024). Effects of unstable load vs stable load on muscle activation and bar velocity during a bench press [Conference abstract]. Graduate Journal of Sports Science, Coaching, Management, & Rehabilitation, 1(3), 32. https://doi.org/10.19164/gjsscmr.v1i3.1514
Cuenca-Fernández, F., Smith, I. C., Jordan, M. J., MacIntosh, B. R., López-Contreras, G., Arellano, R., & Herzog, W. (2017). Nonlocalized postactivation performance enhancement (PAPE) effects in trained athletes: A pilot study. Applied Physiology, Nutrition, and Metabolism, 42(10), 1122–1125. https://doi.org/10.1139/apnm-2017-0217
Drinkwater, E. J., Pritchett, E. J., & Behm, D. G. (2007). Effect of instability and resistance on unintentional squat-lifting kinetics. International Journal of Sports Physiology and Performance, 2(4), 400–413.
Jirovska, R., Kay, A. D., Tsatalas, T., Van Enis, A., Kokkotis, C., Giakas, G., & Mina, M. A. (2023). The influence of unstable load and traditional free-weight back squat exercise on subsequent countermovement jump performance. Journal of Functional Morphology and Kinesiology, 8(4), Article 167. https://doi.org/10.3390/jfmk8040167
Jones, P., & Lees, A. (2003). A biomechanical analysis of the acute effects of complex training using lower limb exercises. Journal of Strength and Conditioning Research, 17(4), 694–700.
Lake, J. P., & McMahon, J. J. (2018). Within-subject consistency of unimodal and bimodal force application during the countermovement jump. Sports, 6(4), Article 143. https://doi.org/10.3390/sports6040143
Lawrence, M. A., & Carlson, L. A. (2015). Effects of an unstable load on force and muscle activation during a parallel back squat. Journal of Strength and Conditioning Research, 29(10), 2949–2953. https://doi.org/10.1519/JSC.0000000000000955
McMahon, J. J., Suchomel, T. J., Lake, J. P., & Comfort, P. (2018). Understanding the key phases of the countermovement jump force-time curve. Strength and Conditioning Journal, 40(4), 96–106. https://doi.org/10.1519/SSC.0000000000000375
Moir, G. L., Mergy, D., Witmer, C., & Davis, S. E. (2011). The acute effects of manipulating volume and load of back squats on countermovement vertical jump performance. Journal of Strength and Conditioning Research, 25(6), 1486–1491. https://doi.org/10.1519/JSC.0b013e3181da8597
Ottinger, C. R., Hall, K. M., Shepherd, S. A., Campbell, A. J., & Biscardi, L. M. (2025). The mechanical loading continuum and its application in strength and conditioning and rehabilitation. Strength and Conditioning Journal, 47(2), 205–214. https://doi.org/10.1519/SSC.0000000000000868
Owen, N. J., Watkins, J., Kilduff, L. P., Bevan, H. R., & Bennett, M. A. (2014). Development of a criterion method to determine peak mechanical power output in a countermovement jump. Journal of Strength and Conditioning Research, 28(6), 1552–1558. https://doi.org/10.1519/JSC.0000000000000311
Rassier, D. E., & MacIntosh, B. R. (2000). Coexistence of potentiation and fatigue in skeletal muscle. Brazilian Journal of Medical and Biological Research, 33(5), 499–508.
Saeterbakken, A. H., & Fimland, M. S. (2013). Muscle force output and electromyographic activity in squats with various unstable surfaces. Journal of Strength and Conditioning Research, 27(1), 130–136.
Sale, D. G. (2002). Postactivation potentiation: Role in human performance. Exercise and Sport Sciences Reviews, 30(3), 138–143. https://doi.org/10.1097/00003677-200207000-00008
Simonelli, C., Rossi, A., Merati, G., Malagoli Lanzoni, I., & Nigro, F. (2024). Acute effects of different warm-up protocols on jump performance in elite male Italian handball players. Applied Sciences, 14(23), Article 11000. https://doi.org/10.3390/app142311000
Sirieiro, P., Nasser, I., Dobbs, W. C., Willardson, J. M., & Miranda, H. (2021). The effect of set configuration and load on post-activation potentiation on vertical jump in athletes. International Journal of Exercise Science, 14(4), 902–911. https://doi.org/10.70252/CCLW6758
Smith, J. C., & Fry, A. C. (2007). Effects of a ten-second maximum voluntary contraction on regulatory myosin light-chain phosphorylation and dynamic performance measures. Journal of Strength and Conditioning Research, 21(1), 73–76.
Stevenson, M. W., Warpeha, J. M., Dietz, C. C., Giveans, R. M., & Erdman, A. G. (2010). Acute effects of elastic bands during the free-weight barbell back squat exercise on velocity, power, and force production. Journal of Strength and Conditioning Research, 24(11), 2944–2954.
Sugisaki, N., Kurokawa, S., Okada, J., & Kanehisa, H. (2014). Difference in the recruitment of hip and knee muscles between back squat and plyometric squat jump. PLoS ONE, 9(6), Article e101203. https://doi.org/10.1371/journal.pone.0101203
Sweeney, H. L., Bowman, B. F., & Stull, J. T. (1993). Myosin light chain phosphorylation in vertebrate striated muscle: Regulation and function. American Journal of Physiology–Cell Physiology, 264(5), C1085–C1095. https://doi.org/10.1152/ajpcell.1993.264.5.C1085
Verducci, T. (2025, April 29). Paul Skenes is aiming to break baseball’s ultimate barrier. Sports Illustrated. https://www.si.com/mlb/paul-skenes-rise-of-pitching-velocity-baseball-ultimate-barrier-digital-cover
Wallace, B. J., Kernozek, T. W., White, J. M., Kline, D. E., Wright, G. A., Peng, H.-T., & Huang, C.-F. (2010). Quantification of vertical ground reaction forces of popular bilateral plyometric exercises. Journal of Strength and Conditioning Research, 24(1), 207–212. https://doi.org/10.1519/JSC.0b013e3181c3b841
Weber, K. R., Brown, L. E., Coburn, J. W., & Zinder, S. M. (2008). Acute effects of heavy-load squats on consecutive squat jump performance. Journal of Strength and Conditioning Research, 22(3), 726–730. https://doi.org/10.1519/JSC.0b013e3181660899
Wezenbeek, E., Verhaeghe, L., Laveyne, K., Ravelingien, L., Witvrouw, E., & Schuermans, J. (2022). The effect of aquabag use on muscle activation in functional strength training. Journal of Sport Rehabilitation, 31(4), 420–427. https://doi.org/10.1123/jsr.2021-0245
Wilson, J. M., Duncan, N. M., Marin, P. J., Brown, L. E., Loenneke, J. P., Wilson, S. M. C., Jo, E., Lowery, R. P., & Ugrinowitsch, C. (2013). Meta-analysis of postactivation potentiation and power: Effects of conditioning activity, volume, gender, rest periods, and training status. Journal of Strength and Conditioning Research, 27(3), 854–859.
Yoon, J., Shiekhzadeh, A., & Nordin, M. (2012). The effect of load weight vs. pace on muscle recruitment during lifting. Applied Ergonomics, 43(6), 1044–1050.
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